Percy Jackson and the Zygon Campaign
by Forever the Optimist
Summary: When campers start acting possessed, no one knows what's going on. No one, that is, until a mysterious man in a blue box falls out of the sky and sweeps Percy and Annabeth away on a whirlwind adventure through the stars to save their friends and get Camp Halfblood back to normal - as normal as it ever gets. I don't usually do crossovers, but this is for a contest, so check it out!
1. Katie Gardner Loses Her Mind

If there's anything I've learned as a half-blood, it's control. We control our ADHD by learning to fight, we get perfect control of our bodies. If you're me, you get controlled by every god or immortal ever to cross your path. I've seen it all. But no matter the experience, no matter what gets thrown at me, I've always been able to control my own mind. But today, that was about to change.

It all started one morning when I was out overseeing some new-camper training. Kids were sword fighting, throwing spears and javelins, and launching arrows at straw dummies. A Hephaestus girl was throwing a shield for my hellhound, Mrs. O'Leary. I was dueling three young Apollo kids at once. Chiron says it's good training for everyone involved, but I still thrashed them easily. Apollo may be good at archery, but they're rubbish sword fighters.

"Keep your guard up, Trevor!" I yelled as I smacked him in the shoulder with the flat of my blade. He rubbed the offended area and I tapped the other shoulder. "And don't ever tend to an injury while there's still an enemy!" A girl, Marlene, rushed me from the side. Rather than blocking her sword, I jumped back. She stumbled forward, not meeting the expected resistance, and I brought Riptide up to rest gently on her neck. "Don't let momentum take away your balance. Stay in control," I told her, pulling my sword away to meet the next attack. I was about to swing at the third camper, Miranda, when I heard someone calling my name.

"Percy! Percy?" Travis Stoll ran into the arena. He bent over, catching his breath, then turned to me. "Percy, message from the Big House."

I disarmed Miranda with a neat trick I learned from Luke my first day here. "Keep practicing," I told them, capping Riptide and sticking it back in my pocket, now a ball point pen. "First one to figure out how that works gets off KP for a week." Being head of the Poseidon cabin has its advantages. The three kids jumped into action as I jogged over to Travis.

"What's up?" I asked him.

"Chiron wants to see you," he told me. "They didn't tell me why."

I nodded. I saw Chiron almost every day, but usually if he wanted to talk to me, he'd come down to the arena. This had to be big.

"Thanks Travis, " I said, heading for the door. "I'll be there as soon as I can."

* * *

Annabeth was waiting for me on the porch of the Big House. Her face was extremely grim.

"Took you long enough," she greeted me.

"Nice to see you too." I gave her a quick kiss on the cheek. "So what's going on?"

"Come in and see," she answered, although she was smiling. We went into the game room that also doubled as our meeting area. Chiron and Mr. D were sitting around the ping pong table playing two hands of pinochle each.

"Ah, excellent!" exclaimed Mr. D, tossing us each a stack of cards. "Sit down and play."

Annabeth shook her head. "Mr. D," she began, setting down the cards, "I really don't think-"

"Nonsense, Annabel," he blustered, drowning out the rest of her sentence. "There is always time for pinochle. Don't you agree?" he added, turning to Chiron. A light flickered in his eyes that I knew only too well. It usually meant _Agree with me or I'll turn you into a porpoise._ That sort of thing.

"Actually, sir," Chiron said delicately, "I do think we have rather more important matters to be dealing with."

Annabeth and I braced ourselves for the explosion, but Dionysus merely sighed.

"I suppose you might be right," he grumbled. He waved his hand and the cards disappeared. In their place was the newest edition of _Wine Enthusiast._ The god buried his nose in the magazine, seemingly losing all interest in us. Chiron hid a smile.

Annabeth cleared her throat. "Chiron, what exactly are we here for?"

I raised an eyebrow. Usually Annabeth knows this sort of thing long before I do. Apparently we were both in the dark.

"Ah yes," Chiron said, rising out of his wheelchair. I have never been able to figure out how he fits an entire horse body into that tiny chair. The Hephaestus kids might know. "Come with me, children."

He led us up the stairs to the second floor of the Big House, his hooves clopping on the wooden stairs. We went down a short hallway to a wooden door. Chiron took out a key from his saddlebag and unlocked it. I didn't have enough time to wonder what they were keeping up here that needed to be locked in before we found ourselves in a cozy little bedroom. And sitting on the bed was -

"Katie Gardner?" I asked, puzzled. "What're you doing here?"

Katie stood up and turned toward us. "Hello Percy, Annabeth," she said, smiling. "How are you today?"

"Just fine, thanks," Annabeth answered cautiously. "Is everything alright?"

"Absolutely. Perfectly. I've never been better." Her expression was perfectly pleasant, but something seemed...off. I turned to Chiron.

"Why is she here?" I demanded. "What's wrong with her?"

"One of her cabinmates brought her in," he told me. "Evidently they were out in the forest looking for a rare plant, they got separated, and when they found her, she wasn't acting the same. As for what's wrong with her, well."

He gestured me closer. "Look at her eyes," he said quietly.

I stepped forward and peered into Katie's dark brown eyes. She stared back at me quizzically.

"What's the matter, Percy?" she asked. As she spoke, I saw it: for a split second, her eyes flashed red.

I jerked back, glancing over at Annabeth, wondering if she'd seen it as well. Her ashen face was all the answer I needed.

"What was that?" I asked Chiron, backing away. I felt my hand straying to my pocket where I kept Riptide and quickly crossed my arms. No matter what was wrong with her, this was still Katie, still my friend. I wasn't about to pull a sword on her, even if the hairs on the back of my neck were screaming at me to do something.

Chiron gave me a long, indecipherable glance, then cantered towards Katie.

"My dear, what is your message?"

Before I could ask what he meant, Katie stood up, sauntering over to stand in front of him. Her expression was cruel and mocking, and not at all like her. Her eyes flashed red again.

"We have come," she said, smiling at him as if this were a perfectly normal conversation. "We seek the power of the Chosen One, the most powerful. He will be taken. He will be ours."

"Well that's ominous," I said, trying to keep my voice light. But Annabeth turned to Chiron, furious.

"'He will be taken'," she repeated, glaring at him, her grey eyes stormy. "So you brought him right to them? Right into their hands?"

"We needed the information," Chiron replied, his voice level, although his tail was swishing back and forth. "That's all she will say on the subject, over and over again. I believed that bringing in a new stimulus might trigger something else, something we could use."

"Um, not to be rude," I jumped in, "but what is she talking about? The Chosen One?"

Chiron and Annabeth both looked at me like I was an idiot.

"Oh," I said, the penny dropping. "You mean me. I'm the Chosen One."

"The Chosen One has identified himself. The rest will be called," Katie said. It was the matter-of-fact way she said it that really creeped me out. The Katie Gardner I knew was sweet and gentle - nothing like the person that stood before me.

"The others?" I asked her. "What others?"

Katie closed her eyes, a look of exhilaration filling her face. "My family," she whispered. "My family is coming. Soon, so soon, they will be here. And you," she said, turning to me, her voice matter-of-fact. "You will come with us."

She walked towards me, arms outstretched, as though ready to grab me then and there. I reached for Riptide, but Annabeth grabbed my arm.

"Percy, no!" she cried, yanking me towards the door. "Just get out, Katie might still be in there!"

I hesitated for a second, then let Annabeth pull me along. We dashed down the hall, Chiron cantering after us and slamming the door behind him. We didn't stop 'til we reached the game room.

Mr. D glanced up from his magazine. "Ah. Back from your little _experiment,_ are we? Well Pedro? Annie? Satisfied? Learned all you could?"

"Sir, you are being unkind," Chiron said reprovingly.

"Blast that," Dionysus said dismissively. "I got sent here to train them, not _be kind_ to them." He buried his nose in his magazine, staunchly ignoring us.

"Chiron, what was that?" Annabeth asked. "I've never seen anything like it, never read of anything that can do that? Is Katie a monster now? Possessed? Some kind of spirit? Or maybe-"

"All good guesses, Annabeth," Chiron said gently, "but I'm afraid I just don't know. I've never encountered such a thing either, in my travels or my readings. That's why I called you here," he said to me. "I was hoping she might give something away."

"Well?" I asked. "What did you learn?"

Chiron sighed. "Not as much as I'd like to," he said. "But some, yes. I must consult with my brethren. Perhaps they have heard of such a thing."

Chiron is the most civilized centaur I've ever met, and I've actually met quite a few. Most of his relatives, the Party Ponies,are complete nut-jobs, although they do come through in a pinch. I was skeptical that they would know anything, but Chiron seemed to think so.

"You two get going," he said to us. "Keep your eyes open. We have no idea what this might be."

We nodded and headed out of the room.

"Don't forget," Chiron called after us. "Capture the Flag tonight!"


	2. Clarisse Knocks Me Out

Capture the Flag was a tradition at Camp Halfblood, one of the first things I ever did here. There's two teams, usually Red and Blue, each made up of various cabins, with one leader. This time Annabeth was leading Red, I was leading Blue. It promised to be interesting.

For our team, we had Apollo, Aphrodite, Demeter, Hephaestus, and Poseidon, which is just me. Red had Athena and Ares, a dangerous team, as well as Dionysus and Hermes. After supper we all got suited up and headed to the creek, which serves as the boundary line between teams.

Chiron met us there, his quiver slung over his shoulder and bow at the ready.

"Campers, I want a fair, clean fight," he called, looking in particular at some of the Ares campers. Clarisse, the leader of the Ares cabin, caught me looking at her and made a rude gesture. We get on so well.

"Campers, you know the teams, you know the rules, you know the game, so all I will say is: good luck!"

We all cheered and I led my team into the woods. Generally the strategy is hiding the flag somewhere noticeable and guarding it well, but I had something different in mind. Annabeth had said something earlier this week, before we knew what cabins were on what teams, and I had a feeling it just might work.

We jogged deeper and deeper into the woods, finally stopping beneath a massive willow tree. I looked over my team.

"You there, what's your name?" I asked a frightened little Demeter girl. She blushed at being singled out.

"Emily," she half-whispered.

"Emily," I repeated. "Can you take this," I handed her the flag, "and climb up as high in that tree as you can. Keep the flag with you and get the tree to hide you, if you can. Don't come down until the game is over, and don't let anyone know you're here, alright? And if anyone tries to climb up, drop an arrow on them." She giggled. "Do you think you can do that?"

"I think so," she said with a grin. She patted the tree trunk and its branches swished.

"Nia, James, give her a boost, will you?" I said to two of the bigger Hephaestus kids. They nodded and cupped their hands together, forming a step. "The rest of you come with me."

As I headed towards the borderline, I saw the branches of the tree boosting the little girl towards the top, the flag clutched tightly in her little hands. And people say Demeter kids are useless.

I led the rest of the Blue Team towards the creek, stopping just out of sight. "Okay, here's the plan. Demeter, Aphrodite: border patrol. Don't let anyone get across that creek. Apollo, Hephaestus, fan out and search. Anyone gets wind of their base, get there and fire a signal arrow."

The Apollo campers grinned and patted their quivers. I could only guess what sort of terrible tricks they kept loaded.

"And no cheating or unnecessary maiming," I reminded them. "We don't want to leave them any openings."

They all nodded. I looked them all over one last time, then nodded. "Alright team, let's do this!"

The two cabins left cheered, then scattered into the woods. I uncapped Riptide and jogged towards the creek. None of the Red Team campers were there yet, I was pleased to see. That was one advantage of a quick hiding spot - it gave us the edge on time.

I waded through the water, feeling the familiar rush of adrenaline I get, courtesy of my dad. I jumped out, clothes perfectly dry, and started through enemy territory.

I hadn't gone far when I heard voices. Well, one voice in particular, one voice I knew very well.

"What do you think you are, punk? Stay away!"

Clarisse. Daughter of Ares, leader of her cabin, and my enemy since my first day here when I doused her in toilet water (long story). Normally I'd go around her and avoid a fight, but if she was pulverizing someone on my team, I had to go in.

"Get back, ugly! Yah!"

I heard the crackle of electricity, probably from her spear, Maimer (or as we call it, Lamer), and an odd, gurgling whisper. I was pretty sure that didn't come from a camper. I pushed my way closer, fighting my way through trees and shrubs. I felt like I had to be dreaming, but Clarisse sounded almost afraid.

"Don't touch me, you miserable roach! I am a daughter of Ares, do you hear me? I am-"

Clarisse's angry shouts were cut off abruptly. I saw a flash of white light and heard her scream. Shoving my way through the last bit of greenery, I burst into a clearing to find Clarisse, crumpled on the ground. And next to her was standing...another Clarisse?

She turned to look at me, the standing one, I mean. Instead of the loud, brash anger we all know and love, I saw something else on her face: a hard, calculating assessment, like she was trying to guess how hard I'd be to kill.

"Clarisse. What's going on?"

"Percy Jackson," she said, rolling my name around as if savoring the sound. "It is Percy, isn't it? Oh, she's got some perfectly horrible memories in here of you. It's no wonder she hates you. But admires you too, oh yes. The wonderful, powerful, _heroic_ Percy Jackson." She smiled cruelly. "Yes, we have chosen well."

I couldn't even begin to process that. Had this… thing, whatever it was, hijacked Clarisse's memories? Or was this Clarisse? The Clarisse I know would never admit to admiring me, even if it was true, which I doubted. So what was this?

"Nice of you to drop by, but I've got places to be. Your turn will come, don't worry. Why don't you…Oh, what's the phrase." She cocked her head sideways, as though thinking. "Ah yes." Her eyes flashed red, and that's when I knew I was in trouble. "Catch forty winks? Or maybe you'd prefer forty volts?"

Before I could react, the standing Clarisse snatched up her spear from the fallen one and pointed it directly at me. There was a sharp zap, the smell of ozone, and then the bolt hit me.

I felt like I'd been kicked in the chest by a pegasus. I flew back, smacking into a tree and crumpling to the forest floor. Every bit of my body hurt. I couldn't talk, couldn't think, couldn't move. All I could do was lay there listening to my heartbeat pounding in my ears, watching as one Clarisse threw the other over her shoulder and ran off into the forest. And then, thankfully, I blacked out.

* * *

When I came to, I was sure someone had snuck in while I was out and filled my whole body with lead. It seemed like too much work to open my eyes, so I tried to figure out what I could by feel alone.

I was in a bed of some kind, still (thankfully) dressed. I tasted homemade brownie, a weird but surprisingly good thing to wake up to. The brownies tasted just like my mom's, so I figured someone had been feeding me ambrosia and nectar, the magical healing food of the gods.

"Percy?"

It was Annabeth; I knew that voice. I forced my eyelids open and her face swam into view. I smiled up at her.

"Oh Percy, thank the gods. When Chiron found you in the woods, nobody knew what to think."

I rubbed my eyes, trying to get them to focus properly. I was in the Big House, I saw, in what served as an infirmary. "How long was I out?"

"Only a few hours," she answered. "You missed dinner." She nodded towards a muffin sitting on the dresser next to my bed.

"What happened with Capture the Flag?" I asked.

"You won," Annabeth said grudgingly. "We couldn't find your flag no matter how hard we tried. It wasn't until after Michael got our flag across the creek that Emily would let on that she was there. She was so wrapped up in branches she looked like a cocoon."

I grinned, proud of my plan and my team.

"Finally a strategy you couldn't beat, huh?" I teased her. She merely sniffed.

"So what happened, Percy? Your heart almost stopped! If Chiron hadn't found you when he did, well…" She trailed off, as if unable to even voice the thought. I took her hand.

"It was Clarisse," I told her. "Except it wasn't. There was two of her, and one of them blasted me with that stupid spear, and then she carried the other one off, and then I passed out, so-"

"Percy, slow down," Annabeth said, a look of concern filling her face. "Clarisse was there for Capture the Flag, right 'til the end. You're not making any sense."

"None of this makes any sense," I grumbled, but I took a deep breath and started over. "Okay, I don't know how it happened, but there's two Clarisses, and I think one of them isn't human. It's like with Katie," I said, seeing her open her mouth to ask the inevitable questions. "The same red eyes, and she talked weird, just like Katie. I could tell it wasn't her, except it was."

Annabeth looked at me. Most people would need time to process something wild like that, but I could tell her mind was already humming away, trying to find a solution to this puzzle.

"This isn't Greek," she said finally, her eyes a million miles away. "It can't be. I...I need to go research…" She stood up and drifted out of the room.

"Annabeth, wait!" I called, struggling to get out of bed. "Annabeth!" But she was already gone. I sighed. Annabeth is smart, no doubt about it, but when she goes into her thinking modes, no one else exists. I try to keep an eye on her, though, to make sure she does the little things. Like eat, for example.

I threw off the covers and got to my feet, ignoring the pounding in my head. I grabbed the muffin, breaking off a chunk and stuffing it into my mouth before making my way out the door. With any luck, I'd catch up to her before she went too far.


	3. I Almost Get Hit By A Phone Booth

An hour later, I found her sitting under a massive old oak tree just inside the camp's magical border. She had the laptop that Daedalus gave her propped up on her knees.

"Found at last," I said, settling myself on the ground next to her. "Can't hide from me, you know."

She gave me a shove. "Shut up, Seaweed Brain."

"Oh, there's the Annabeth we all know and love. So what're you learning?"

"Nothing," she said, closing the laptop with a snap. "Absolutely nothing. I've gone through all of Daedalus' notes, all his records, and nothing matches up. We just don't know enough!"

And that, I could see, was what was really bothering her: the not knowing. Athena kids are always looking for answers, for neat solutions, but it's pretty hard to put a puzzle together when you've only got half the pieces.

"Well, look on the bright side," I said, trying to be encouraging. "We've only known about this for what, a day?" There's only so much you can figure out right away, you know. Give it time."

Annabeth sighed. "Yeah, I suppose you're-"

She broke off suddenly, staring behind me, her eyes wide. I glanced back over my shoulder.

"What?" I asked. Nothing seemed out of the ordinary to me. "What do you see?"

"That shouldn't be possible," she murmured, getting to her feet and clutching her laptop close to her chest.

"What?" I asked again. I stood up too, turning around, and only then did I see what Annabeth was watching: a bright blue box, hurtling through the sky at breakneck speed. As it got closer, I could read the words 'Police Public Call Box' across the top.

"What in Hades…" I muttered, but I didn't have time to think about it much longer. "Duck!" I yelled as the box crashed through the trees, heading right for us.

Annabeth and I hit the dirt, and I was certain we were going to be crushed, but the thing ricocheted off our protective border, creating a sunburst of yellow light where it connected. It bounced back, crashing into a tree and falling forward. For a moment it looked as though it would fall over, but then the edge was caught by the border, sending up sparks where it touched, but coming to rest at last.

I looked carefully at Annabeth, who was ghost-white. She shrugged and pulled out her dagger, getting cautiously to her feet. I followed her lead, uncapping Riptide, and we crept over to the police box door.

There was a thud, and a crash, and then the door creaked open. Annabeth and I glanced at each other, then dove into a bush.

"Never let an enemy see you before you have to," she whispered. I nodded. We had no idea what might come out, or whether or not we'd have to fight it, but any advantage is a good one.

A man in a brown pinstripe suit staggered out, coughing, followed by clouds of smoke. For some reason, he was soaking wet. He looked around for a moment, taking everything in, then stuck his head back in the door.

"Extrapolator fans on!" he yelled, then slammed the doors shut. I could hear a whirring that must have been the fans… but no, that was ridiculous. Phone boxes didn't have fans. Then again, phone boxes didn't fall out of the sky, either.

"Do you think he's a god?" I asked Annabeth quietly. She shook her head.

"He'd have been able to get through the barrier then," she answered. "Besides, who ever heard of a British god?"

He did have a decidedly British accent. But I wasn't so sure. Whoever he was, he had an aura of power about him, like someone who's been around for ages and has seen worlds burn. I've met my share of immortals, and this guy felt like one to me.

The man now turned to where his box - I assumed it was his - was resting against the border. It was still sparking and flaring. He slipped on a pair of rectangular glasses and stepped closer.

"Now that's interesting," he said to himself. He reached out and laid a hand on the magical wall, watching the light jump and dance curiously. "Very interesting... How did you stop the TARDIS from getting through, eh?" he asked it. "There's not a thing on this planet that can do that. Shouldn't be, anyway."

It was the eyes, I decided. His eyes were so incredibly old, and sad, just like Chiron's. But he had an air of self-confidence, too. He knew what he could do and was comfortable in his own skin, in a way I'd only ever seen before in a god. I thought I'd be extra polite to him, just in case. Gods tend to vaporize you if you don't treat them with respect.

The man reached into a jacket pocket and pulled out a long silver metal gadget with a blue light on the end. He flicked it and the end extended, lighting up with an odd, pulsing sound. He pointed this device at various parts of the border, then held it close to his face.

"What is that?" I whispered to Annabeth. I'd never seen anything like it before. She only shrugged, her eyes never leaving the strange man.

"Oh, that's fun," he said, compressing the thing back to its original form and returning it to his pocket. "Gods and demigods only, I see. Greek, I'd assume. Explains more than it doesn't. So I'd need an invitation…" He turned and looked directly at our hiding place. "Don't suppose you'd let me in?"

Annabeth and I looked at each other, slightly guilty, and shrank further into the bush.

"Come on," he called encouragingly. "No use pretending I don't know you're there, now is there? It's so much nicer when we can talk face to face."

I glanced at Annabeth and shrugged. Then together we stood up and approached the man, sword and dagger at the ready.

"Oh, put those down," he said, waving us off. "They won't do you any good. Celestial bronze, am I right?" I nodded in spite of myself. "Won't hurt me at all. But I'm not dangerous, I promise. See?" He raised his hands to the sky. "Totally unarmed."

"What about that metal thing?" I asked suspiciously.

"What, this?" He pulled out that same device and flipped it end over end into the air. "It's just a screwdriver. A sonic screwdriver. Made it myself." He beamed at us. "Doesn't kill, doesn't main, doesn't wound. That's just why I like it. I'm the Doctor, by the way."

I put Riptide away, although I kept my hand in my pocket. I'd been taken in too many times to trust someone this strange. He might be unarmed, but I was sure he could be pretty dangerous if he chose.

"Doctor who?" Annabeth asked. I noticed she still had her dagger out.

"I love it when people say that," he said, grinning. "Just the Doctor. And that's my TARDIS."

"TARDIS?" I repeated. "What's that?"

"Time And Relative Dimensions In Space," the Doctor rattled off. "She's my time machine. But enough about that," he said, seeing Annabeth open her mouth to ask a question. I knew that would drive her crazy - she hates not being able to figure things out, and time travel, well… I wasn't sure I believed it myself. "You haven't had any troubles with Zygons recently, have you?"

* * *

 **A.N: Hey, everybody! Here you have all that I have of my brand new story and first ever crossover! I didn't much think I was going to enjoy it, but it's been interesting so far, and I'm pretty excited. My primary motivator remains finishing it off so I can get back to my other story, Mystery Girl, which my personal favorite thing I have ever written. So yeah! I can't say exactly when this'll be done, but the deadline is October 2, so stay tuned! Much love!**

 **-Forever the Optimist**


	4. The Doctor Is In

"Zygons?" I repeated, stumbling a bit over the unfamiliar word. "What's a Zygon?"

"Big red rubbery alien," the Doctor answered, as though this were perfectly normal. "Venomous sacks in the tongue. Very nasty. But," he added, holding up a hand, "they have got some pretty impressive biological technology."

He had Annabeth interested now. "Biological technology? How does that work?"

The Doctor grinned at her. "Curious. I like that." Annabeth blushed slightly, and I elbowed her. "They combine their natural biological abilities with advanced technology," he explained. "Specifically, they can perfectly mimic many other creatures, like horses, cows, dogs-"

"And humans," I guessed. He nodded. "Is that what happened to Katie and Clarisse? With the red eyes?"

"Lost some friends, have you? I thought so," he said. "Although the red eyes is a bit odd. Always red?"

"No, just flashes," Annabeth answered. I could see pretty clearly she already admired the Doctor a lot. Takes a genius to know one, I suppose.

"Just flashes…" he muttered. "Never known that to happen before. You two are demigods, yes?"

We nodded. I still didn't know what this Doctor was for sure, but I was pretty convinced he was no monster, and no danger to us.

"Fantastic," he said, beaming. "I haven't run into a demigod for years. And your friends, they're demigods too?"

We nodded again.

"Could explain it," he said to himself. "Zygons aren't meant to interact with ichor. Incompatible genetic mixes. Might be causing problems… Anyway, I started picking up some communication lines and traced them here. Kept going on about 'blood of the gods' and 'the true power.' Good stuff like that," he told us with a grin. "So!"

He stepped over to his box - his TARDIS, I told myself - which was still leaning against our barrier. "You going to let me in?"

I hesitated a moment, but Annabeth recited, "I, Annabeth Chase, give the Doctor and his TARDIS permission to enter Camp Halfblood."

Suddenly, the barrier disappeared and the TARDIS crashed to the ground. Fortunately, the door was facing up.

"Excellent," the Doctor said, rubbing his hands together. He snapped his fingers and the doors swung open. Smiling at us, he jumped up to sit on the edge. "I'll just pop in and set her upright, and then we'll be off!"

"Off?" I asked. "Off where?"

He looked at me like I'd grown a second head. "Off to find the Zygons, of course. Where else?"

I didn't say anything. It seemed to me there was no way it could really be that simple, but then again, this all seemed very impossible. I tried to keep an open mind.

"Well," the Doctor said brightly. "Back in a mo', then." He swung himself into the box and let go. His entire body disappeared, and the doors swung shut.

"Where did he go?" Annabeth asked, staring in fascination. "He shouldn't have fit, not in that tiny thing."

But this was very quickly the least of our marvels. The TARDIS starting making a wheezing, groaning noise, and then, before our very eyes, started to fade out of sight.

"Look away!" I yelled, averting my eyes. I was sure that this Doctor was a god after all and was about to reveal his true form, which would incinerate anyone who looked at it. But Annabeth kept watching, and after a moment, I looked back.

The TARDIS was now completely gone, but as I watched, it started to come back into view, this time right side up. Before long it was solid again. Annabeth stepped forward, running a careful hand along the side.

"It's definitely real," she murmured. "Just wood and paint. But how…"

The door creaked open and the Doctor poked his head out. "Well?" he asked. "You coming?"

I glanced over at Annabeth. I wasn't too keen on going anywhere with this guy, especially in a flying box. I didn't have the greatest history with air travel. But Annabeth's eyes were alive with curiosity, and I knew this would be the chance of a lifetime for her. Plus, this could be the only chance we had to get Katie and Clarisse back, and stop these Zygon things from doing any more damage.

Annabeth was looking at me, waiting for me to say yes. I think she could tell I wasn't too happy about all of this.

"I won't go without you," she whispered. I swallowed hard, then grabbed her hand.

"We're coming," I said. And we stepped forward into the TARDIS.

And stopped. Inside that tiny little box was an enormous room, way larger than should be possible. Huge coral-like structures wound their way up to the ceiling, like supports. There was a raised plinth in the center of the room, with what looked like a control panel in the center, covered in lights and buttons and levers and who knows what else. All I could do was stare.

The Doctor was leaning on this control panel, hands shoved deep in his pockets. "Go on, say it," he called. "Everybody does."

"It's… It's… bigger on the inside!" Annabeth gasped. "How is that possible? You're not a god, not a monster…" The Doctor chuckled.

"I'm a Time Lord," he said. "The last of the Time Lords. From the planet Galifrey, in the constellation Kasterborous. I'm 904 years old, and I'm here to help you save your friends. Got a problem with that?"

"No, no problem," I said. Annabeth was still in shock. Her knuckles were white where they clenched her laptop, and I felt like my hand was being crushed.

"Good," he said, giving me a grin and a sharp nod. "Then we're off. Allons-y!" He pulled a lever and the tube above the console starting moving up and down, making that same wheezing noise we heard before.

"That's French," Annabeth whispered. "For 'Let's go.' What kind of alien speaks French?" But I could tell she was starting to calm down. Her grip on my hand relaxed, and some color was coming back into her face.

"We'll be there soon," the Doctor called. He strolled over to it, hands in his pockets. "Well? What do you think? I know this can be a bit… overwhelming."

"Why is it wet?" I asked. The Doctor plucked ruefully at his sopping sleeve.

"Ah, right. Nasty crash," he explained. "Might have spilled the swimming pool a bit."

"Swimming pool?" This I had to see. Son of Poseidon, remember. I like swimming pools.

"Didn't I mention?" He grinned. "Bigger on the inside. Infinitely bigger, actually. Of course there's a pool. Now if you'll excuse me," he added, cutting off any further questions, "I'm going to go change. We'll have landed soon."

He ducked off through a door off to the side, leaving us alone in the control room. I wandered up to the console, fingering some of the buttons and trying to make sense of some of the screens. Annabeth came up behind me.

"So what do you think?" I asked, not looking at her.

"It's… impossible," she said hesitantly. "And incredible, and amazing. The amount of technology that went into this, the design… this completely revolutionizes dimensional theory. Just think, Percy!" she said, excited now. "If we could do this with all our buildings, humanity could keep growing forever. We'd never need to worry about housing or land preservation ever again! Not to mention the art…"

I have to admit, I sort of tuned her out at that point. Annabeth is a huge architecture nut, and she talks about it any chance she gets. I try to listen, but most of it goes over my head. I could tell how huge this would be for her, though.

"...and temples! Bigger on the inside temples, and-"

"Still here, are we?" the Doctor called, appearing in the doorway and bounding up the ramp to the platform. He was wearing a suit identical to the first, except dry. "Good. All adjusted too, I hope. Now," he said, grabbing a box from underneath the ramp and dragging it up, "those celestial bronze weapons won't do you any good here. These monsters are just as mortal as me, and maybe even more so. So I found you something else."

He pulled out a huge broadsword and tossed it to me. I caught it instinctively and looked it over. It was big, much bigger than Riptide, and heavier too, but it had a longer reach and a good balance. I could work with this.

"Got that off the Sycorax leader, Christmas Day," the Doctor told us. "Challenged him to a duel for the planet. He cut off my hand, but I beat him in the end. Got a new hand, too," he added, waving his hands in the air. I decided not to comment.

"And for you," he said to Annabeth, "the personal dagger of Henry the Eighth. Not Greek, I know, but still good enough. He's a rubbish dice player."

Annabeth took the offered blade and examined it. Then, with a nod, she slid it into her belt.

"Now I don't want you to kill if you don't have to," he warned us. "These aren't monsters like you know them, they don't just come back. They're people, of a sort, with minds and personalities and a right to life, just like you or me. Keep it in mind, eh?"

We nodded. I felt a bit like a kid going into a store and being told not to touch anything, but I figured if he was giving me a sword, I'd probably have something to use it on.

"Right then," he exclaimed, flashing us that grin, "here we are!" He dashed to the doors and threw them open. "Welcome to the Zygon ship."

* * *

 **A.N: Alright, here we go! Another chapter for you all, and I hope you enjoyed it! It's really weird to have to make sure every sentence is in character, and I'm really not used to it, but I hope I've done decently well. I've got a 10k word limit, so hopefully this'll wrap up soonish, although it'll probably be longer on here. I usually end up trimming for that competition. Again, can't promise when the next one will be up, but hopefully in the next few days. Thanks for reading, and please review!**

 **-Forever the Optimist**


	5. I Duel Myself to the Death

Annabeth and I peered out of the TARDIS doors into the Zygon complex. It was very dark and earthy, almost like a cave, and smelled faintly of iron. The ship was mostly just one big round room, with a few smaller doorways on either side. There was a raised walkway running around the edge of the room, and this was where we had landed. And, of course, there were Zygons everywhere. Easily eight feet tall, they were huge and red and disgusting. So, fairly typical monster.

Across the room, against the back wall, were vaguely human figures draped in an odd, red, stringy material that looked really gross. There were tubes coming out of each, leading to bags full of a golden liquid I recognized as ichor, the blood of the gods. The Doctor pointed to those.

"See that?" he whispered. "That's where they're keeping your friends, under all that. Biological technology, see? That's how they're keeping the copies down in your camp alive, keeping them real. And filtering their blood, I would guess. That's up to you two," he told us. "Get over there, get them free, get them back to the TARDIS. Now look there."

He pointed towards a sort of control panel. "That's where I'm going. I'll decommission the ship and send it back to Zygor, where, if I'm very clever, and I'm more than clever, I'm brilliant, it will eject them all and then self-destruct. So they'll be back home, you have your friends, everybody's happy. Good, eh?"

"So what's the catch?" I asked. I'd been in enough battles to know that things never go exactly according to plan.

"Right, the catch." The Doctor grinned, rubbing his hands together. "Two things. One, Zygons have venomous barbs on their palms that'll stun, maim, or kill, depending on their mood, so watch out for that. Two, they're probably going to try to get you into one of those," he added, pointing towards where Katie and Clarisse were trapped, "Harvest the power of your immortal blood. Don't let them touch you and you should be fine. Got all that? Good."

I grinned and hefted my sword. This was something I could handle, something I knew I was good at.

"Now for a little distraction…" the Doctor murmured, pulling out his sonic screwdriver and raising it above his head. He pressed a button and the screwdriver made a high-pitched squealing noise that reminded me of a screaming Stymphalian bird. All across the room, Zygons were writhing in pain, hissing and gurgling and lashing out.

"Now!" roared the Doctor, and he vaulted over the railing of the walkway, landing on his feet and sprinting towards the control panel. Annabeth and I followed, dodging the screaming Zygons in our dash to the back.

We only made it about halfway before they started recovering. "Percy!" Annabeth screamed. "Behind you!"

I spun around, raising my sword. A massive Zygon was standing just to my left, hands raised and ready. He advanced towards me, and I did the instinctive thing: I slashed at him.

The cut was long and deep, right across the thing's chest. Its eyes widened, full of a dumb surprise I'd seen so many times. Then it crumpled to the ground, a puddle of blood spreading out around it. I swallowed hard. It was so much easier when monsters just disintegrated - killing these was much more real.

"Percy, get moving!" Annabeth screamed, snapping me back to reality. I turned and ran towards our Zygon-covered friends. Annabeth was already there, pulling at the red stringy things. Clarisse was already mostly uncovered, and she was spitting mad. Annabeth had wisely left her head for last. I grabbed a handful of the Zygon junk and pulled. It came off in my hands and I flung it away, disgusted. Soon Clarisse was free.

"Just let me at 'em," she spat, yanking the tube out of her arm and grabbing for her spear. Finding it gone didn't make her any happier. "I'll pulverize them all!" She leapt towards the nearest Zygon, hands out as if to throttle him. I tossed my sword aside and lunged at her, grabbing her arms and holding her back.

"Clarisse, stop," I grunted, as she fought to get away. "If they touch you they turn into you, and celestial bronze won't work." She stopped fighting and I let her go, panting. "Help Annabeth get Katie out, okay?"

She glared at me, but stomped off. Annabeth glanced up, then turned ghost white. "Percy-"

And that's when I felt a rubbery hand on my neck. Instantly I remembered the Doctor's words: _Zygons have venomous barbs on their palms that'll stun, maim, or kill, depending on their mood._ I wrenched away, throwing myself at the floor.

My training took over. I rolled to my feet, sword at the ready. I looked for the Zygon, but they were all holding back, watching. Instead, there stood a guy with dark hair and sea-green eyes, wearing an orange Camp Halfblood T shirt and holding my new sword. I looked down at myself, then at him. Same outfit. Out of the corner of my eye I saw a long, thin barb stuck into my sleeve - a Zygon stinger. I plucked it out and held it carefully, concealed in my palm.

The other Percy grinned at me. "Hello, me," it said, putting the sword point-down on the earthy floor and leaning easily on it. "Nice to see you at last."

I glanced at him critically. "Is that really what I look like?"

The Zygon-me shrugged. "I'm afraid so. Not a pretty sight, is it?"

I decided to ignore that. "What do you want?"

"What do you think?" it asked, twirling the sword. "You know I can't possibly allow you to get away with this. The blood of the gods… The power is too good to pass up. And you, especially…" The Zygon shook his head, eyes flashing red. "You have more power than we even dared hope. I can feel it," he said, looking down at his stolen body. "Humming through my veins, trying to force me out. But we can control it," he added, looking around at the other gathered Zygons. "We can tame it, as I have tamed it, and it will propel us to the very ends of the universe!"

The other Zygons cheered - at least, I think it was cheering. I gritted my teeth.

"Yeah, but how's that going for you?" I called. "Red eyes, that's not supposed to happen, is it? Is the ADHD kicking in? Your control is slipping already, and what happens if you lose it completely?"

The gathered Zygons hissed. The other me turned around, trying to calm them down. I glanced at Annabeth. She had Katie completely uncovered and was edging her way around the walkway, making her way towards the TARDIS with the other two in tow. I figured she'd be okay if I could keep them distracted.

"Almost there," I heard the Doctor call. "Biotech and sonic, not a great mix. I really must get a software update. Buy some time, can you?"

I nodded, though I knew he couldn't see me, and stepped towards the Zygon me, who I guessed was some kind of leader. Just my luck. He turned back to face me, raising his sword.

"You are correct," he told me. "The power is great, and dangerous. But you, Percy Jackson, can help us." His eyes flashed red and his face twisted in a cruel smile, something I never wanted to see myself do again. "The blood of the gods is fighting us, fighting our control. But if you submit, if you come willingly and agree to help us, then the power is ours."

"And in return?" I asked. "I'm not nice enough to do this just out of the goodness of my heart, you know."

The Zygon Percy glared at me. "We will spare your life," he told me.

"Generous offer," I remarked. "But I've got a better plan. How about you let me and my friends get off this ship unharmed. Then I might leave some of you alive."

He sneered. "A stalemate, then. But I've seen your memories, Percy Jackson. Suppose we do things your way: trial by combat? Win, and you and your friends go free. Lose, and we get your energy, including that of the Time Lord."

He hefted the massive Sycorax sword, handling it like he knew how to use it. Handling it like I would. This was going to be tough, I realized. This thing was me, with all my strength and knowledge and reflexes. How do you beat yourself?

I uncapped Riptide. I wasn't even sure the celestial bronze would work, but this thing was me now. Hopefully that meant he could be hurt by the same things I could.

"Well," I said, pretending to think it over. "If you really want to, I guess I accept your offer."

Before I was really finished with my word, I lunged, a long stab that would pierce him through the heart. Unfortunately, he knew that trick, and dodged aside, flicking his sword up to slice my ribs. I dove out of the way, rolling several times to take me out of the fight so I could get to my feet.

The other Percy grinned at me, feral and thrilled. Then, on some unspoken command, we rushed together, locking swords and straining to gain the upper hand.

I tried frantically to think: what advantages did I have? We were perfectly matched, of course, but there had to be differences. He had the Sycorax sword, which gave him a longer reach and more power behind each stroke. However, it was also balanced slightly differently, which would hopefully throw him off, and it weighed more. In the long run, I was better off.

But the long run hardly ever matters in the long run. I needed something immediate, something to finish this quickly before something went wrong.

We disengaged, spinning apart. I ducked in, trying to disarm him, but he saw it coming and blocked, sending shocks down my arms and nicking my ribs. I saw blood, but there was nothing I could do about it now.

 _There has to be something,_ I thought. _Some little thing, something I've forgotten…_ My side felt like it was on fire as we slashed and dodged, neither able to gain the upper hand. And then it hit me.

I darted forward, catching his sword in my own and locking them together once more. My arms were shaking, and I could tell his were too. For a moment, we struggled, first one way, then the other. The weight of his sword pressing down, then my extra energy.

I looked into the Zygon's eyes, eyes I knew were identical to mine. "You won't ever be me," I told him, both hands gripping Riptide's hilt for as much leverage as possible. "Not really, not ever. And you know why? Because I am human, I am real, and that is something you can never really be. You will only ever be a fake."

In every battle, there is a tip in the momentum, that moment instinctively hardwired into me that only training and knowledge can develop. The time an opponent typically presses forward and gives their last attempt. You have to be in control to find it, have to be calm and aware, taking in every detail of what's going on around you.

I knew it was coming, and maybe the Zygon did too. But he got angry, just like I'd hoped he would, and shoved down at me with all his strength. I braced myself, bearing up under the weight, and grinned up at my double.

"What happens when you lose control?" I asked him. "How would you like to find out?" With that, I let go of the sword hilt with one hand. The sudden dip in resistance sent him lurching forward, and as he crashed to the ground, I stabbed him in the neck with the venemous barb he'd left in my shirt.

The Zygon Percy screamed, falling to his knees and grabbing frantically at the sting embedded in his skin. His eyes burned red, and parts of his body started to stretch and distort, like it was switching between Zygon and demigod. Watching my own body changing like that was pretty gross, and I was starting to feel like throwing up, so I looked away.

When I looked back, all traces of Zygon were gone, with just me left - my body, dead on the floor. I stared down at it.

"You know what happens?" I said softly. "You lose." Then I capped Riptide and stepped over him to face the gathered Zygons.

"Your leader is dead," I called, looking around the group. I grabbed up the sword the Doctor had lent me and held it over my head. "Will you honor his terms?"

For a moment, it seemed like they wouldn't. But then, one by one, the Zygons bowed their rubbery heads and cleared a path to let me through.

Annabeth and the Doctor were waiting for me outside the TARDIS. Annabeth was beaming, although she was still pale. The Doctor raised an eyebrow.

"Not bad," he told me. "Not bad at all."

I handed him the sword, hilt first. "Take it back," I said. "I'll stick with mine in the future."

The Doctor nodded. "A wise choice, I think." He started to turn away, then stopped. "You could have left him alive, though."

I looked at him, keeping my voice level. "You really think so?"

He shrugged. "There's always a better way. But yours was better than most." He inclined his head slightly, then stepped into the TARDIS.

Annabeth gave me a hug. "Percy, that was brilliant! Using their own venom against them, how did you know it would work?"

I shrugged. "I didn't," I admitted. "Lucky guess."

She elbowed me. "Typical Seaweed Brain," she said, but she took my hand, and we walked into the TARDIS together.


	6. Epilogue: I Almost Get Dumped for a Box

I stood in the woods, under that same tree where I'd found Annabeth only a few hours before. The TARDIS was standing in front of me, doors pulled tightly shut. The Doctor was inside, giving Annabeth a lesson on Time Lord engineering.

Katie and Clarisse were already back in camp, celebrating and vowing revenge over Capture the Flag. The Doctor told us that they probably wouldn't have much memory of the whole experience, which was fine with me. We had enough monsters to worry about as it is.

And me? I was happy just to be home. There's a whole universe out there, sure, just waiting to be explored. New horizons, new monsters, new everything. But I'd already had my world rocked once in my lifetime, and there was so much I didn't know about Greek mythology, so much I could see right here. Why would I want to leave?

Just then the TARDIS doors creaked open. Annabeth came out, her eyes dancing.

"It's amazing, Percy!" she said, almost breathless. "The things they can do...all of time and space in a little box! And the dimensional engineering…"

The Doctor grinned at her. "Simple technology," he told us. "You've only seen the basics. It'd take years to learn it all, and you've just begun."

"I wish I could," Annabeth said. "It's fascinating, and if we could replicate it here at Camp Halfblood, we'd never have trouble with monsters again."

"Well," the Doctor said musingly, "you could come with me."

"What?" Annabeth asked, stunned.

"Come with me," he repeated. "See the stars, learn all there is to know. I haven't got anyone to travel with right now, and, well…"

I have to admit, I started to panic. Here was the chance of a lifetime for her: flying around in a magical time machine, seeing everything, everywhere, learning all the time. But somehow I didn't think I'd be invited along. I flashed back to when I thought Annabeth was going to join the Hunters.

"Annabeth," I blurted, "you-" I stopped. Yes, Annabeth was my girlfriend, and I didn't want to lose her. But I couldn't keep her from this, not if she really wanted it. "You have fun," I finished, forcing out the words. "Kick some alien butt for me."

Annabeth stared into the TARDIS, and the longing was plain on her face. But after a moment, she looked away.

"Thank you, Doctor," she said, smiling, "but I belong at Camp Halfblood." She walked over to stand next to me, and as I took her hand in mine, I swear I've never been happier.

The Doctor nodded, running a hand through his hair. "Right. Of course. You've got a place, you don't need to wander. But you were great, you know. Both of you. Absolutely fantastic."

He stepped back, leaning against the doors of the TARDIS. "Well, I'll be off, then," he said, pulling out a gray pocket watch and checking it. "Lots to do before tomorrow." He stowed it back in his pocket, then started to close the door. "Stay out of trouble, and watch out for Mother Earth. She bites."

"Watch out for who?" I asked, but he was already gone. Soon the TARDIS started its wheezing groan and began to fade out of sight. The wind blew my hair back and made my eyes water, but I watched until the little blue police box was gone.

Annabeth sighed. "What an adventure," she said, leaning in to my shoulder. I put my arm around her.

"Yeah," I agreed. "And not one I really want to repeat." She nodded, although there was something slightly wistful in her eyes. "Now come on," I said, giving her a little shake. "I've got a Capture the Flag victory to celebrate."

She looked up at me, her gray eyes sending me a challenge. "Is that so?"

"Yep. And I think it's time to claim my prize."

I grabbed her waist and kissed her cheek. She latched onto my wrist and judo flipped me over her hip into a bush. I came up with a mouth full of leaves.

"You'll pay for that!" I yelled, climbing out of the shrubbery.

"Not if you can't catch me," she taunted me, keeping just out of reach. Laughing, I chased her towards camp, thinking that no galaxy could ever replace just being here.


End file.
